Inductor and method of manufacturing inductor

ABSTRACT

An inductor ( 100 ) includes a pair of magnetic members (cores ( 10, 20 )), a main body having coils ( 71, 72 ), and a sheet-formed fixation member ( 60 ), wherein the fixation member ( 60 ) is bound across the cores ( 10, 20 ) and the main body, to thereby fix the cores ( 10, 20 ) which configure a closed magnetic path, and to thereby fix at least one of the cores ( 10, 20 ) to the main body.

This application is based on Japanese patent application No.2014-097616, filed on May 9, 2014, the content of which is incorporatedhereinto by reference.

BACKGROUND

1. Technical Field

The present invention relates to an inductor used in particular fortransformer, and a method of manufacturing the inductor.

2. Related Art

There has been known an inductor having a plurality of cores assembledto configure a closed magnetic path, wherein the plurality of cores arefixed by winding a tape around them. This sort of inductor is typicallydisclosed in JP-U-H05-28012.

According to JP-U-H05-28012, the plurality of cores have trenchesprovided on the outer circumferential surfaces thereof, and are fixed inan abutted manner by winding the tape while guided by the trench. Byvirtue of provision of the trench, positional variation of winding maybe suppressed, and workload of a worker who winds up the tape may bereduced.

When a closed magnetic path is formed in this sort of inductor byinserting a part of the core into the coil, only a simple winding of thetape will fail to prevent relative positional shift of the coil and thecore, and will fail to achieve target specification. It is thereforenecessary to take some steps to fix the relative positional relation.

It has therefore been necessary to spend some additional workload and toprepare a specialized jig used for such work for every product, whichhas caused a problem from the viewpoint of productivity.

SUMMARY

The present invention was conceived to solve the problems describedabove, and an object thereof is to provide an inductor which contributesto improve the productivity, and a method of manufacturing suchinductor.

According to the present invention, there is provided an inductor whichincludes a pair of magnetic members, and a main body having a coilconfigured by a wound wire,

a rod-like insertion part of one magnetic member, out of the pair ofmagnetic members, being inserted into the coil, the one magnetic memberbeing combined with the other magnetic member to configure a closedmagnetic path, and, the closed magnetic path including as a part thereofthe insertion part, the inductor further includes a sheet-formedfixation member, the fixation member being bound across the one magneticmember and the other magnetic member and the main body, to thereby fixthe one magnetic member to the other magnetic member, both configuringthe closed magnetic path, and to thereby fix at least one of the pair ofmagnetic members to the main body.

According to the present invention, there is also provided a method ofmanufacturing an inductor which has a pair of magnetic members, and amain body having a coil configured by a wound wire, the method includes:configuring a closed magnetic path, by inserting a rod-like insertionpart of one magnetic member, out of the pair of magnetic members, intothe coil, and combining the one magnetic member with the other magneticmember to configure a closed magnetic path which includes as a partthereof the insertion part; and

fixing the closed magnetic path, by binding a sheet-formed fixationmember across the one magnetic member and the other magnetic member andthe main body, to thereby fix the one magnetic member to the othermagnetic member, both configuring the closed magnetic path, and tothereby fix at least one of the pair of magnetic members to the mainbody.

When the present invention is applied, a single fixation member (i)binds and fixes one magnetic member to the other magnetic member, and(ii) binds and fixes at least one of the pair of magnetic members to themain body, so that relative shift in position of the pair of magneticmembers and the main body may be suppressed. Accordingly, in the processof fixing the relative position of the magnetic member and the coil, thepositional shift may be suppressed in a successful manner, and theworkload required for the process may be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, advantages and features of the presentinvention will be more apparent from the following description ofcertain preferred embodiments taken in conjunction with the accompanyingdrawings, in which:

FIG. 1 is a perspective view illustrating an inductor of a firstembodiment viewed from the negative side on Z-axis;

FIG. 2 is a perspective view illustrating the inductor of the firstembodiment viewed from the positive side on Z-axis;

FIG. 3 is an exploded view of the inductor viewed from the directioncorresponded to FIG. 1;

FIG. 4 is an exploded view of the inductor viewed from the directioncorresponded to FIG. 2;

FIG. 5 is a bottom view of the inductor;

FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 5;

FIG. 7A is a bottom view of a second member;

FIG. 7B is a perspective view of the second member viewed from thebottom;

FIG. 8 is a schematic drawing illustrating positions where an end partof a bobbin part is brought into contact with ribs;

FIG. 9 is a schematic drawing illustrating a closed magnetic pathconfigured by coils and cores;

FIG. 10 is a flow chart illustrating a method of manufacturing theinductor; and

FIG. 11 is a perspective view illustrating an inductor of a secondembodiment.

DETAILED DESCRIPTION

The invention will be now described herein with reference toillustrative embodiments. Those skilled in the art will recognize thatmany alternative embodiments can be accomplished using the teachings ofthe present invention and that the invention is not limited to theembodiments illustrated for explanatory purposes.

Embodiments of the present invention will be explained referring to theattached drawings. In all drawings, all identical constituents will begiven the same reference numerals and/or symbols, so as to avoidrepetitive explanation for the convenience.

Various directions in this embodiment will be explained according to arectangular coordinate system represented by X-axis, Y-axis and Z-axisindicated in the individual drawings, unless otherwise specificallynoted. X-axis lies in the vertical direction of the inductor whenmounted on a board (not illustrated), where the direction from thebottom towards the top in FIG. 1 is defined as the positive direction.Z-axis lies in the longitudinal direction of the coil 70 (coil 71 andcoil 72), where the direction from lower left towards upper right inFIG. 1 is defined as the positive direction. Y-axis lies in thedirection vertical to X-axis and Z-axis, where the direction from lowerleft towards upper right in FIG. 1 is defined as the positive direction.

First Embodiment

An inductor 100 of the first embodiment will be outlined referring toFIG. 1, FIG. 2, FIG. 5 and FIG. 6.

FIG. 1 is a perspective view illustrating the inductor 100 of the firstembodiment viewed from the negative side on Z-axis. FIG. 2 is aperspective view illustrating the inductor 100 of the first embodimentviewed form the positive side on Z-axis. FIG. 5 is a bottom view of theinductor 100. FIG. 6 is a cross-sectional view taken along line VI-VI inFIG. 5.

The inductor 100 has a pair of magnetic members (core 10 and core 20),and main body 50 having a coil 71 and a coil 72 configured by a woundwire. A rod-like insertion part 12 of one magnetic member (core 10), outof the pair of magnetic members, is inserted into the coil 71. Arod-like insertion part 22 of the other magnetic member (core 20), outof the pair of magnetic members, is inserted into the coil 72. The core10 and the core 20 are combined to configure a closed magnetic path,and, the closed magnetic path includes as a part thereof the insertionparts 12, 22.

The inductor 100 further includes a sheet-formed fixation member 60. Thefixation member 60 is bound across the core 10 and the core 20 and themain body 50, to thereby fix the core 10 and the core 20, bothconfiguring the closed magnetic path, and to thereby fix at least one ofthe core 10 and the core 20 to the main body 50.

With such configuration, the fixation member 60 can fix the pair ofmagnetic members (core 10 and core 20) and the main body 50 together.

Now, the inductor 100 refers to an article having a portion (coil 70,for example) in which inductance generates when supplied with electriccurrent. While such portion in the inductor 100 of this embodiment isdivided into two (coil 71 and coil 72), this is not essential. In otherwords, the potion may be configured by a single coil, or by three ormore coils. Applications of the inductor 100 are exemplified bytransformer and choke coil.

Now, the phrase of “the fixation member 60 is bound” means that thefixation member 60 is connected to a target member, and also encompassesthe case where the fixation member 60 is adhered using an adhesive, andthe case where the fixation member 60 is attracted with the aid offrictional force, magnetic force or static electricity.

In this embodiment, the longitudinal direction of the fixation member 60lies in the YZ-plane, and the widthwise direction of the fixation member60 lies in the X-axis direction.

Both of the core 10 and the core 20, which are the pair of magneticmembers, have an E shape, and have the insertion part 12 inserted intothe coil 71, and the insertion part 22 inserted into the coil 72. Thepair of magnetic members in the present invention are not only thosehaving a combination of E-shape core and E-shape core, but may also bethose having a combination of E-shape core and I-shape core. Itconsequently suffices that at least one of the magnetic members has aportion equivalent to the insertion part 12 or the insertion part 22.

With the features described above, a single fixation member 60 (i) canbind and fix the core 10 and the core 20, and (ii) can bind and fix atleast one of the core 10 and the core 20 with the main body 50, so thatrelative shift in position of the pair of magnetic members and the mainbody may be suppressed. Accordingly, in the process of fixing therelative position of the core 10 and the coil 71, or, relative positionof the core 20 and the coil 72, such positional shift may be suppressedin a successful manner, and the workload required for the process may bereduced.

<Coil 70 and Main Body 50>

Next, the coil 70 and the main body 50 will be described referring toFIG. 1 to FIG. 8.

FIG. 1 is a perspective view illustrating the inductor 100 of the firstembodiment viewed from the negative side on Z-axis. FIG. 2 is aperspective view illustrating the inductor 100 of the first embodimentviewed from the positive side on Z-axis. FIG. 3 is an exploded view ofthe inductor 100 viewed from the direction corresponded to FIG. 1. FIG.4 is an exploded view of the inductor 100 viewed from the directioncorresponded to FIG. 2. FIG. 5 is a bottom view of the inductor 100.FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 5. FIG.7A is a bottom view of a second member 40. FIG. 7B is a perspective viewof the second member 40 viewed from the bottom. FIG. 8 is a schematicdrawing illustrating positions where an end part 34 of a bobbin part 38is brought into contact with ribs 415, 416.

The main body 50 is a constituent of the inductor 100 which includes atleast the coil 70 (coil 71 and coil 72) and a member which houses thecoil 70. In this embodiment, the member which houses the coil 70includes the bobbin part 38, a bobbin part 39, a base part 51 and acover part 41. The main body 50 in this embodiment also includes,besides the above-described parts, a plurality of terminal parts 31 (311to 318).

The main body 50 in this embodiment has a first member 30 and the secondmember 40. The main body 50 is configured by winding a winding wirearound the bobbin parts 38, 39 to form the coil 70, then by combiningthe first member 30 and the second member 40, and further by coveringthe coil 70 with the cover part 41.

The configuration of the main body 50 illustrated here is merely anexample, and may be modified in various ways. For example, the may body50 may be configured by a single member, or may be configured bycombining three or more members.

The coil 70 includes the coil 71 disposed on the core 10 side (morenegative side on Z-axis), and the coil 72 disposed on the core 20 side(more positive side on Z-axis). The coil 71 and the coil 72 are equallyparted by a partition part 35 and a partition part 36.

The coil 71 is connected to four terminal parts 311 to 314 disposed onthe core 10 side. The coil 72 is connected to four terminal parts 315 to318 disposed on the core 20 side.

The first member 30 is made of a thermosetting resin such as phenolresin, or thermoplastic resin, and is an electrical insulator, so thatthe coil 71 and the coil 72 are electrically isolated by the partitionpart 35 and the partition part 36. Since the coil 71 and the coil 72share a single closed magnetic path, so that when current flows in oneof them, the current flows in the other by mutual induction.

With such configuration, the inductor 100 is applicable to transformer,choke coil and so forth. The number of turns of the coil 71 and the coil72, and types of the winding wire are selectable depending on targetspecifications of the inductor 100.

The cover part 41 has a projection part 411 provided on the core 10side, but has no part equivalent to the projection part 411 on the core20 side. The projection part 411 is provided to allow the user toexternally identify the arrangement of the coil 71 and the coil 72 whichare invisible under the cover part 41. When the inductor 100 is mountedon a board (not illustrated), directionality of mounting may bedetermined with reference to the projection part 411.

In a gap between the partition part 35 and the partition part 36, thereare formed a partition part 45 and a partition part 46, provided in thesecond member 40, so as to fall therein. The second member 40 is made ofa thermoplastic resin such as nylon, or a thermosetting resin, and is anelectric insulator, so that also the partition part 45 and the partitionpart 46 serve to keep a creepage distance necessary for electricallyisolating the coil 71 and the coil 72. The partition part 45 and thepartition part 46, held between the partition part 35 and the partitionpart 36 so as to properly function as described above, also function toprevent positional shift between the first member 30 and the secondmember 40 in the X-axis direction.

The first member 30 includes the bobbin part 38 and the bobbin part 39.

The bobbin part 38 is a hollow tubular article having the coil 71 formedon the exterior thereof, and having the insertion part 12 insertedtherein. The bobbin part 38 is flanged at the end part 34. The bobbinpart 39 is a hollow tubular article having the coil 72 formed on theexterior thereof, and having the insertion part 22 inserted therein. Thebobbin part 39 is flanged at the end part 37.

The second member 40 has ribs 415, 416 on the inner wall of the coverpart 41, which are provided so as to oppose with the end part 34, and soas to protrude from the inner wall towards the end part 34. The secondmember 40 also has ribs 417, 418 on the inner wall of the cover part 41,which are provided so as to oppose with an end part 37, and so as toprotrude from the inner wall towards the end part 37.

The second member 40 is press-fitted onto the first member 30 along theend part 34 and the end part 37, so that the end part 34 is brought intoclose contact with the ribs 415, 416, and the end part 37 is broughtinto close contact with the ribs 417, 418. With such configuration, thefirst member 30 and the second member 40 are prevented from shifting inthe Z-axis direction.

The ribs 415 to 418 are tapered towards the end parts 34, 37, that is,thinned from the base ends towards the tips. With such geometry, theribs 415 to 418 per se will be given a sufficient level of strength, andwill smoothen the press-fitting of the second member 40 to the firstmember 30.

FIG. 8 illustrates areas A4, A5 where the ribs 415, 416 are brought intoclose contact with the end part 34.

The end part 34 includes an opening 341 through which the insertion part12 is inserted. The ribs 415, 416 extend nearly linearly along the innerwall of the cover part 41.

As illustrated in FIG. 8, the areas A4, A5 reside outside of the area A1which falls beyond the opening 341 in the direction of press-fitting ofthe second member 40 (X-axis direction). The areas A4, A5 also resideoutside of areas A2, A3 which fall beyond the opening 341 in thedirection normal to the direction of press-fitting of the second member40 (Y-axis direction). In other words, the positions where the ribs 415,416 reside fall outside of the opening 341 at the end part 34, whenviewed whichever from the direction of press-fitting of the secondmember 40, or from the direction normal to the direction ofpress-fitting.

Now “outside of the opening 341” means areas which do not overlap theopening 341 when viewed from a predetermined direction which lies alongthe end part 34.

Similarly to the end part 34, also the end part 37 includes an openingthrough which the insertion part 22 is inserted. Similarly to the ribs415, 416, again the ribs 417, 418 extend nearly linearly along the innerwall of the cover part 41, and positions where the ribs 417, 418 residefall outside of the opening 371 at the end part 37, when viewedwhichever from the direction of press-fitting of the second member 40,or from the direction normal to the direction of press-fitting.

As described above, the ribs 415 to 418 are brought into close contactwith the first member 30. Accordingly, even if the second member 40,after press-fitted to the first member 30, should shift in the X-axisdirection or in the Y-axis direction, the ribs 415, 416 will not reachthe opening 341, and the ribs 417, 418 will not reach the opening 371.Accordingly, in the process of press-fitting, the load possibly appliedby the ribs 415 to 418 to the end parts 34, 37 will not be concentratedin the vicinities of the openings 341, 371, and thereby the end parts34, 37 are prevented from deforming. As a consequence, with sucharrangement of the ribs 415 to 418 described above, it is ensured thatthe insertion parts 12, 22 may smoothly be inserted into the openings341, 371.

The first member 30 has a leg part 32 having the base ends of theterminal parts 311 to 314 embedded therein, and a leg part 33 having thebase ends of the terminal parts 315 to 318 embedded therein. The secondmember 40 includes, besides the cover part 41 described above, the coverskirt 42 which is positioned below the cover part 41 and protrudes outfrom the cover part 41 in the Y-axis direction and in the Z-axisdirection. The cover skirt 42 embraces the leg part 32 and the leg part33. The second member 40 is press-fitted to the first member 30, deeplyuntil the top face of the inner wall of the cover skirt 42 and the topfaces of the outer walls of the leg part 32 and the leg part 33 arebrought into contact.

In other words, the top face of the inner wall of the cover skirt 42 andthe top faces of the outer walls of the leg part 32 and the leg part 33serve as the reference faces for the process of press-fitting of thesecond member 40 to the first member 30.

<Closed Magnetic Path Configured in Inductor 100>

The second member 40 has openings 412, 413 provided to the cover part41, at positions opposed to the openings 341, 371. The insertion part 12is inserted through the opening 412 and the opening 341 into the bobbinpart 38. The insertion part 22 is inserted through the opening 413 andthe opening 371 into the bobbin part 39.

Next, a closed magnetic path configured in the inductor 100 will bedescribed referring to FIG. 9.

FIG. 9 is a schematic drawing illustrating the closed magnetic pathconfigured by the coil 70 and the cores 10, 20. In more details, FIG. 9is a schematic drawing of the inductor 100, from which the constituentsother than the cores 10, 20 and the coil 70 are removed, virtuallyillustrating an electromagnetic field generated when the coil 70 issupplied with electric power.

Now the closed magnetic path means a closed loop of magnetic pathgeometrically approximated to the magnetic member, formed by shieldingmagnetic flux which generates from the coil 70 intrinsically in adivergent manner, by the magnetic members (core 10 and core 20) providedaround the coil 70, to thereby converge the magnetic path of suchmagnetic flux into the magnetic member.

The phrase of “closed magnetic path is configured” means that the coil70 is given a form capable of configuring the closed magnetic path whensupplied with electric power. More specifically, the core 10 and thecore 20 are designed, when combined, to form a frame (including thosehaving annular, polygonal or other shapes), sphere, box or the like, inwhich the coil 70 may be embraced.

As illustrated in FIG. 9, the core 10 and the core 20 have analphabetical “E” shape and an inverted “E” shape, respectively, whenviewed in the X-axis direction. The core 10 is configured by an outerframe part 11, the insertion part 12, outer frame part 13 and an outerframe part 14. Of these constituents, the insertion part 12 is insertedinto the coil 71, whereas the outer frame part 11, the outer frame part13 and the outer frame part 14 are disposed outside the coil 71. Thecore 20 is configured by an outer frame part 21, the insertion part 22,an outer frame part 23 and an outer frame part 24. Of theseconstituents, the insertion part 22 is inserted into the coil 72,whereas the outer frame part 21, the outer frame part 23 and the outerframe part 24 are disposed outside the coil 72.

When the core 10 and the core 20 are combined, an end face 111 of theouter frame part 11 and the end face 211 of the outer frame part 21, anend face 121 of the insertion part 12 and the end face 221 of theinsertion part 22, and an end face 131 of the outer frame part 13 and anend face 231 of the outer frame part 23 are brought into contactrespectively, (see FIG. 3 and FIG. 4, for a layout of the individual endfaces). In this way, the core 10 and core 20 configure a frame as awhole, in which the insertion part 12 and the insertion part 22 areenclosed.

While the embodiment has been described that all of three sets,represented by the outer frame part 11 and the outer frame part 21, theinsertion part 12 and the insertion part 22, and the outer frame part 13and the outer frame part 23, were respectively brought into contact witheach other, the embodiment is not limited thereto. More specifically,apart of, or all of these three sets are not always necessarily broughtinto direct contact. For example, a gap composed of an air layer or aninsulator such as resin may be provided between the two components ofeach of three sets, so as to control electromagnetic characteristics ofthe inductor 100.

It is, however, preferable that in any one of the sets, the twocomponents are brought into direct contact, or brought into indirectcontact while placing something in between. This is because, if the twocomponents in at least one of the three sets are brought into contact,the fixation member 60 can bind the core 10 and the core 20 on the outercircumferential side faces thereof, and so that the closed magnetic pathmay be fixed by tightening the fixation member 60.

The cores 10, 20 and the coil 70 configure a magnetic path M1 and amagnetic path M2. The magnetic path M2 is routed, when assumed to startfrom the insertion part 12, as insertion part 12→outer frame part14→outer frame part 11→outer frame part 21→outer frame part 24→insertionpart 22→insertion part 12. The magnetic path M1 is routed, when assumedto start from the insertion part 12, as insertion part 12→outer framepart 14→outer frame part 13→outer frame part 23→outer frame part24→insertion part 22→insertion part 12. In short, both of the magneticpath M1 and the magnetic path M2 configure the closed magnetic paths.

<Fixation Member 60>

The fixation member 60 will now be described below, referring to FIG. 1,FIG. 2, FIG. 5 and FIG. 6. More specifically, positional relations amongthe core 10, the core 20 and the main body 50 will be made clear, andthen a technique of fixing the closed magnetic path (the frame composedof the core 10 and the core 20) with the fixation member 60 will beexplained.

FIG. 1 is a perspective view of the inductor 100 of the firstembodiment, with the one core 10 directed to the nearer side. FIG. 2 isa perspective view of the inductor 100, with the other core 20, havingbeen directed to the far side in FIG. 1, directed to the nearer side.FIG. 5 is a bottom view of the inductor 100. FIG. 6 is a cross-sectionalview taken along line VI-VI in FIG. 5.

The main body 50 has a base part 51 which is positioned, when mounted ona board (not illustrated), between the board and the pair of magneticmembers (core 10 and core 20) so as to keep the board and the pair ofmagnetic members apart from each other.

As described previously, the core 10 and the core 20, which configurethe closed magnetic path, form a square frame enclosing therein theinsertion part 12.

The fixation member 60 extends over the longitudinal direction thereofaround all of four side faces of the frame, to thereby bind the frame.In this way, the relative positional shift of the main body 50 and thepair of magnetic members (core 10 and core 20) may be suppressed.

While the fixation member 60 exemplified in this embodiment extendsaround all of four side faces of the frame, the embodiment is notlimited thereto. For example, the fixation member 60 may be bound to atleast two adjoining side faces out of four side faces, and, also extendsover a side face of the base part and the two side faces of the frame.This is because binding of at least two adjoining side faces is enoughto suppress relative positional shift of the main body 50 and the pairof magnetic members (core 10 and core 20) in the Y-axis direction andthe Z-axis direction.

The four side faces of the frame described in the previous paragraph arespecifically shown in the next. A first side face is represented by aside face 141 contained in the outer circumference of the outer framepart 14 of the core 10. A second side face is represented by a side face241 contained in the outer circumference of the outer frame part 24 ofthe core 20. A third side face is represented by a plane configured bycombining a side face 112 contained in the outer circumference of theouter frame part 11 of the core 10, and a side face 212 contained in theouter circumference of the outer frame part 21 of the core 20. A fourthside face is represented by a plane configured by combining a side face132 contained in the outer circumference of the outer frame part 13 ofthe core 10, and a side face 232 contained in the outer circumference ofthe outer frame part 23 of the core 20.

The fixation member 60 in this embodiment is preferably a band-likemember having a long side in the longitudinal direction and a short sidein the widthwise direction, and is provided with a tacky adhesive layerhaving tackiness. The fixation member 60 may be an adhesive tape havinga tacky surface preliminarily formed thereon, or may be a band-likemember used by coating thereon an adhesive, when the inductor 100 ismanufactured.

When the fixation member 60 described above is used, the fixation member60 is preferably bound to the pair of magnetic members (core 10 and core20) and the main body 50, while placing the tacky adhesive layer inbetween for adhesion.

By using such fixation member 60, only a simple work (one action), suchas placing the fixation member 60, will be enough to fix the pair ofmagnetic members and the main body 50. Since the binding force isassisted by the adhesive force, the pair of magnetic members and themain body 50 may be bound more tightly as compared with the case wherethey are bound only by a binding force of the fixation member 60.

The fixation member 60 may also be made of a heat shrinkable material.More specifically, the fixation member 60 has a heat shrinkage factor inthe longitudinal direction larger than in the widthwise direction. Theheat shrinkable material is exemplified by easily adhesive syntheticresin materials such as polyphenylene sulfide (PPS), polyvinyl chloride(PVC), and polyethylene terephthalate (PET). The fixation member 60preferably has the melting point higher than reflow temperature ofsolder (for example, 240° C. or above and 250° C. or below), and cantherefore fully shrink in the longitudinal direction under heating atthe reflow temperature. Thus the fixation member 60 can shrink in thelongitudinal direction, under heating when the inductor 100 is mountedon the board (not illustrated) using a solder by the reflow process, andthereby the fixing force between the pair of magnetic members and themain body 50 may be increased.

In the main body 50 in this embodiment, the side faces of the base part51 are preferably recessed inwardly from the side faces of the frame,or, aligned in the same plane with the side faces of the frame.

This is because, with such configuration, even if the fixation member 60should be brought apart from the base part 51, the hem of the fixationmember 60 will not expand outward, so that the hem of the fixationmember 60 may be prevented from being brought into contact withelectronic components (not illustrated) arranged close to the inductor100. This is also because, with such configuration, the tacky adhesivelayer of the fixation member 60 can more readily be adhered to a portionon the frame side of the boundary between the base part 51 and theframe, so that the force of binding the frame by the fixation member 60will effect more fully than in a configuration where the side faces ofthe base part 51 protrude outward from the side faces of the frame.

As described above, the main body 50 in this embodiment is configured bypress-fitting the second member 40 containing the cover part 41 whichcovers the coil 70, onto the first member 30 containing the plurality ofterminal parts 31 which are connected to the board.

The side faces of the base part 51 include first planes 321, 331contained in the first member 30, and second planes 421 to 426 containedin the second member 40.

The fixation member 60 is bound across the first planes 321, 331 and thesecond planes 421 to 426.

Now, the terminal parts 31 are parts used when the coil 70 iselectrically connected to the electrodes on the board (not illustrated),and are connected to such electrodes. As the terminal parts 31 in thisembodiment, there are provided four terminal parts 311 to 314 arrangedon the core 10 side (more negative side on Z-axis), and four terminalparts 315 to 318 arranged on the core 20 side (more positive side onZ-axis).

The first planes 321, 331 can be explained in further detail, asfollows.

The first plane 321 is a side face of the base part 51, contained in theleg part 32 having the base ends of the terminal parts 311 to 314embedded therein, and faced to the negative side on Z-axis. The firstplane 321 is aligned nearly to the same plane with the second plane 421,and aligned to the same plane with the side face 141, or, recessedinwardly from the side face 141.

The first plane 331 is a side face of the base part 51, contained in theleg part 33 having the base ends of the terminal parts 315 to 318embedded therein, and faced to the positive side on Z-axis. The firstplane 331 is aligned nearly to the same plane with the second plane 424,and aligned to the same plane with the side face 241, or, recessedinwardly from the side face 241.

The second planes 421 to 426 can be explained in further detail, asfollows.

The second plane 421 is a side face of the base part 51 faced to thenegative side on Z-axis, and is positioned between the side face 141 andthe first plane 321. The second plane 421 is aligned nearly to the sameplane with the first plane 321, and aligned to the same plane with theside face 141, or, recessed inwardly therefrom.

The second plane 422 and the second plane 423 are side faces of the basepart 51 faced to the positive side on Y-axis. The second plane 422 andthe second plane 423 are recessed from the side face 132 and the sideface 232, respectively.

The second plane 424 is a side face of the base part 51 faced to thepositive side on Z-axis, and is positioned between the side face 241 andthe first plane 331. The second plane 424 is aligned nearly to the sameplane with the first plane 331, and aligned to the same plane with theside face 241 or recessed inwardly therefrom.

The second plane 425 and the second plane 426 are side faces of the basepart 51 faced to the negative side on Y-axis. The second plane 425 andthe second plane 426 are recessed from the side face 212 and the sideface 112, respectively.

Since the core 10, the core 20 and the main body 50 are disposedaccording to the positional relation described above, the fixationmember 60 can be bound to the individual faces as described below.

The fixation member 60 is bound, across the widthwise direction thereof,to the side face 141 of the frame, the first plane 321 and the secondplane 421.

The fixation member 60 is bound, across the widthwise direction thereof,to the side face 132 and the side face 232 of the frame, the secondplane 422, and the second plane 423.

The fixation member 60 is bound, across the widthwise direction thereof,to the side face 241 of the frame, the first plane 331, and the secondplane 424.

The fixation member 60 is bound, across the widthwise direction thereof,to the side face 112 and side face 212 of the frame, the second plane425, and the second plane 426.

The fixation member 60 is bound, over the longitudinal directionthereof, to the side face 141, the side face 132, the side face 232, theside face 241, the side face 212 and the side face 112 of the frame. Inother words, the fixation member 60 extends around all of four sidefaces of the frame.

The fixation member 60 is bound, over the longitudinal directionthereof, to the first plane 321 or the second plane 421, the secondplane 422, the second plane 423, the first plane 331 or the second plane424, the second plane 425, and the second plane 426 of the base part 51.In short, the fixation member 60 extends around all of the side faces ofthe base part 51.

Since the fixation member 60 binds the individual faces as describedabove, the first member 30 and the second member 40 are prevented fromshifting in the longitudinal direction of the fixation member 60 (Y-axisdirection and Z-axis direction), and also from shifting in the widthwisedirection of the fixation member 60 (X-axis direction).

The first plane 321, the second plane 421 and the side face 141 arealigned nearly in the same plane, so that three kinds of components(core 10, first member 30 and second member 40) are bound with eachother, by the fixation member 60 across the widthwise direction thereof.The three kinds of components are therefore prevented from shifting inthe Z-axis direction.

The first plane 331, the second plane 424 and the side face 241 areagain aligned nearly in the same plane, so that three kinds ofcomponents (core 20, first member 30 and second member 40) are boundwith each other, by the fixation member 60 across the widthwisedirection thereof. The three kinds of components are therefore preventedfrom shifting in the Z-axis direction.

<Method of Manufacturing Inductor 100>

Next, a method of manufacturing the inductor 100 will be explained,referring to FIG. 10.

FIG. 10 is a flow chart illustrating the method of manufacturing theinductor 100.

The method of manufacturing illustrated in FIG. 10 is a method ofmanufacturing the inductor 100 which has a pair of magnetic members(core 10 and core 20), and the main body 50 having the coil 70configured by a wound wire. The method of manufacturing includes a stepof press-fitting (S11), a step of configuring the closed magnetic path(S12), and a step of fixing the closed magnetic path (S13).

In step S11, the second member 40 is press-fitted to the first member30, to thereby fix them with each other.

In step S12, the rod-like insertion part 12 of one magnetic member (core10), out of the pair of magnetic members, is inserted into the coil 71.At the same time or a different time the insertion part 12 is insertedinto the coil 71, the rod-like insertion part 22 of the other magneticmember (core 20), out of the pair of magnetic members, is inserted intothe coil 72. In this way, the one magnetic member (core 10) and theother magnetic member (core 20) are combined to configure the closedmagnetic path which includes as a part thereof the insertion parts 12,22.

In step S13, the sheet-formed fixation member 60 is bound across thecore 10, the core 20, and the main body 50, to thereby fix the core 10and the core 20, both configuring the closed magnetic path, and tothereby fix at least one of the pair of magnetic members to the mainbody 50.

By this method of manufacturing, since the fixation member 60 (i) bindsand fixes the core 10 to the core 20, and (ii) binds and fixes at leastone of the core 10 and the core 20 to the main body 50, so that relativeshift in position of these components may be suppressed. Accordingly, inthe process of fixing the relative position of the core 10 and the coil71, or, the core 20 and the coil 72, the positional shift may besuppressed in a successful manner, and the workload required for theprocess may be reduced.

As described previously, the main body 50 in this embodiment has a basepart 51 which is positioned, when mounted on a board (not illustrated),between the board and the pair of magnetic members (core 10 and core 20)so as to keep the board and the pair of magnetic members apart from eachother. The fixation member 60 in this embodiment is a band-like memberhaving a long side in the longitudinal direction and a short side in thewidthwise direction, and is provided with a tacky adhesive layer havingtackiness.

Accordingly, in the step of configuring the closed magnetic path (S12),the pair of magnetic members (core 10 and core 20) may be combined toform a square frame enclosing therein the insertion parts 12, 22.

In the step of fixing the closed magnetic path (S13), (a) the frame andthe base part 51 may be aligned according to a desired positionalrelation, with reference to at least two adjoining side faces out offour side faces of the frame, (b) the fixation member 60 may be adheredover the longitudinal direction thereof to the two faces, and, (c) thefixation member 60 may be adhered across the widthwise direction thereofto the two faces and to the side faces of the base part 51.

The processes (a), (b) and (c) in step S13 may take place in parallel,or independently in a time-series manner.

In the process (a) in step S13, the frame and the base part 51 may bealigned with reference to the both of two adjoining side faces out ofall side faces of the frame, at the same time, or partially in aparallel manner. Alternatively, alignment with reference to one of twoside faces, may be followed by the alignment with reference to theother.

In this process, the frame (core 10 or core 20) and the base part 51(first member 30 or second member 40) may be moved directly by anoperator or a machine, or may be moved indirectly by the binding forceof the fixation member 60 kept under tension.

In the processes (b) and (c) in step S13, adhesion of the fixationmember 60 in the longitudinal direction and in the widthwise directionmay take place at the same time of partially in a parallel manner.Alternatively, adhesion in either one direction may be followed byadhesion in the other direction.

According to the method of manufacturing, since the side faces of theframe (core 10 or core 20) can serve as the reference for alignment, sothat the individual components of the inductor 100 may be aligned intodesired positions, without using any specialized jig.

While the method of manufacturing suitable for this embodiment has beendescribed, on the premise that all of the constituents composing theinductor 100 are preliminarily assorted, the steps are not necessarilythe whole steps of the method of manufacturing the inductor 100. Forexample, the steps described above may be preceded by a step of formingthe cores 10, 20, the first member 30 and so forth, or by a step ofwinding the winding wire around the bobbin parts 38, 39 to thereby formthe coils 71, 72.

Second Embodiment

An inductor 200 of a second embodiment will be outlined below, referringto FIG. 11.

FIG. 11 is a perspective view illustrating the inductor 200 of thesecond embodiment. In more details, FIG. 11 is a perspective view of theinductor 200, with the core 20 directed to the nearer side.

In this embodiment, all components and parts, which are considered to beidentical with those in the first embodiment, will be given identicalnames and reference numerals for the convenience of explanation.

The inductor 200 of this embodiment is different from the inductor 100of the first embodiment, in that adhesives 81, 82 are applied atboundary positions between a part of the cover part 41 which protrudesfrom inside of the frame, configured to contain the core 10 and the core20, in the direction opposite to the base part 51, and the pair ofmagnetic members.

In more details, the adhesive 81 is applied at the boundary positionbetween a point where the outer frame part 11 and the outer frame part21 come into contact, and the side face of the cover part 41 at aroundthe point of contact. The adhesive 82 is applied to a position where theinsertion part (not illustrated) of the core 20 is inserted into themain body 50.

By applying the adhesives 81, 82 in this way, the pair of magneticmembers (core 10 and core 20) and the main body 50 may be fixed moretightly.

Although not illustrated here, the adhesive may also be applied to apoint-symmetrical position as viewed from the point where the adhesive81 or the adhesive 82 is applied, about the center of the pair ofmagnetic members (position of contact of the insertion part of the core10 and the insertion part of the core 20). This is because the pair ofmagnetic members and the main body 50 may be fixed more tightly byapplying the adhesive in this way.

Except for the features described above, the inductor 200 of thisembodiment is same as the inductor 100 of the first embodiment. Variousoperations and effects in this embodiment, which are common to those inthe first embodiment, will not be detailed here.

The present invention has been explained referring to a plurality ofembodiments, merely for illustrative purposes. Each of the variousconstituents described above is not always necessarily an essentialconstituent, instead being omissible so long as the effect of thepresent invention will not be ruined, or being replaceable with theother constituent which functions or acts in the same way.

For example, the paragraphs above have described an exemplary case wherethe winding wire was wound around the bobbin part 38 and the bobbin part39 to form the coil 71 and the coil 72, respectively, the main body 50does not always necessarily have portions equivalent to the bobbin part38 and the bobbin part 39. More specifically, so long as the windingwire which forms the coil is covered with an insulating material, thewinding wire may be wound directly around the cores 10, 20 to form thecoil.

While the paragraphs above have described an exemplary case where thecoil 70 is covered with the cover part 41, the cover part 41 is notessential, and instead the coil 70 may stay exposed.

Each of the various constituents of the present invention is not alwaysnecessarily an independent something that exists, instead allowing thata plurality of constituents are configured to give a single constituent;that a single constituent is formed by a plurality of divisionalconstituents; that a certain constituents is a part of otherconstituent; and that a part of a certain constituent overlaps with apart of other constituent.

For example, while both embodiments explained above dealt with theexemplary cases where the main body 50 has two coils (coil 71 and coil72), the main body 50 may have at least one coil, or the coil 71 and thecoil 72 may be electrically connected to give a single coil.

According to the present invention, there is provided an inductor whichcontributes to improve the productivity, and a method of manufacturingsuch inductor.

It is apparent that the present invention is not limited to the aboveembodiment, and may be modified and changed without departing from thescope and spirit of the invention.

This embodiment also embraces the technical spirits below:

(1) An inductor which includes a pair of magnetic members, and a mainbody having a coil configured by a wound wire,

a rod-like insertion part of one magnetic member, out of the pair ofmagnetic members, being inserted into the coil, the one magnetic memberbeing combined with the other magnetic member to configure a closedmagnetic path, and, the closed magnetic path including as a part thereofthe insertion part,

the inductor further includes a sheet-formed fixation member,

the fixation member being bound across the one magnetic member and theother magnetic member and the main body, to thereby fix the one magneticmember to the other magnetic member, both configuring the closedmagnetic path, and to thereby fix at least one of the pair of magneticmembers to the main body.

(2) The inductor according to (1),

wherein the main body has a base part which is positioned, when mountedon a board, between the board and the pair of magnetic members so as tokeep the board and the pair of magnetic members apart from each other,

the pair of magnetic members, which configure the closed magnetic path,form a square frame enclosing therein the insertion part, and

the fixation member is bound to at least two adjoining side faces out offour side faces of the frame, and, also extends over a side face of thebase part and the two side faces of the frame.

(3) The inductor according to (2),

wherein the fixation member is a band-like member having a long side inthe longitudinal direction and a short side in the widthwise direction,and is provided with a tacky adhesive layer having tackiness, and

the fixation member is bound to the pair of magnetic members and themain body, while placing the tacky adhesive layer in between foradhesion.

(4) The inductor according to (3),

wherein the fixation member extends over the longitudinal directionthereof around all of four side faces of the frame, to thereby bind theframe.

(5) The inductor according to any one of (2) to (4),

wherein the side faces of the base part bound with the fixation memberare recessed inwardly from the side faces of the frame, or, aligned inthe same plane with the side faces of the frame.

(6) The inductor according to any one of (2) to (5),

wherein the main body is configured by press-fitting a second membercontaining a cover part which covers the coil, onto a first membercontaining a plurality of terminal parts which are connected to theboard,

the side faces of the base part bound to the fixation member include afirst plane contained in the first member, and a second plane containedin the second member, and

the fixation member is bound across the first plane and the secondplane.

(7) The inductor according to (6) dependent to (3),

wherein the fixation member is bound, across the widthwise directionthereof, to the side faces of the frame, the first plane and the secondplane.

(8) The inductor according to (6) or (7),

wherein the first member contains a hollow tubular article having thecoil wound therearound, and having the insertion part inserted therein,

the hollow tubular article is flanged at the end part thereof,

the second member has a rib which is formed on the inner wall of thecover part so as to oppose to the end part, and so as to protrude fromthe inner wall towards the end part, and,

the second member is press-fitted along the end part so as to bring theend part into close contact with the rib.

(9) The inductor according to (8),

wherein the end part contains an opening having the insertion partinserted therein,

the rib extends nearly linearly along the inner wall of the cover part,and

the rib extends at a position which falls outside the opening at the endpart, when viewed whichever from the direction of press-fitting of thesecond member, or from the direction normal to the direction ofpress-fitting.

(10) The inductor according to any one of (6) to (9),

wherein an adhesive is coated on a boundary position between a part ofthe cover part which protrude from inside of the frame towards theopposite side of the base part, and the pair of magnetic members.

(11) A method of manufacturing an inductor which has a pair of magneticmembers, and a main body having a coil configured by a wound wire, themethod includes:

configuring a closed magnetic path, by inserting a rod-like insertionpart of one magnetic member, out of the pair of magnetic members, intothe coil, and combining the one magnetic member with the other magneticmember to configure a closed magnetic path which includes as a partthereof the insertion part; and

fixing the closed magnetic path, by binding a sheet-formed fixationmember across the one magnetic member and the other magnetic member andthe main body, to thereby fix the one magnetic member to the othermagnetic member, both configuring the closed magnetic path, and tothereby fix at least one of the pair of magnetic members to the mainbody.

(12) The method of manufacturing an inductor according to (11),

wherein the main body has a base part which is positioned, when mountedon a board, between the board and the pair of magnetic members so as tokeep the board and the pair of magnetic members apart from each other,

the fixation member is a band-like member having a long side in thelongitudinal direction and a short side in the widthwise direction, andis provided with a tacky adhesive layer having tackiness,

in the step of configuring the closed magnetic path, the pair ofmagnetic members are combined to form a square frame enclosing thereinthe insertion part, and

in the step of fixing the closed magnetic path, the frame and the basepart are aligned according to a desired positional relation, withreference to at least two adjoining side faces out of four side faces ofthe frame, the fixation member is adhered over the longitudinaldirection thereof to the two faces, and, the fixation member is adheredacross the widthwise direction thereof to the two faces and to the sideface of the base part.

What is claimed is:
 1. An inductor comprising a pair of magnetic members, and a main body having a coil configured by a wound wire, a rod-like insertion part of one magnetic member, out of the pair of magnetic members, being inserted into the coil, the one magnetic member being combined with the other magnetic member to configure a closed magnetic path, and, the closed magnetic path including as a part thereof the insertion part, the inductor further comprising a sheet-formed fixation member, the fixation member being bound across the one magnetic member and the other magnetic member and the main body, to thereby fix the one magnetic member to the other magnetic member, both configuring the closed magnetic path, and to thereby fix at least one of the pair of magnetic members to the main body.
 2. The inductor according to claim 1, wherein the main body has a base part which is positioned, when mounted on a board, between the board and the pair of magnetic members so as to keep the board and the pair of magnetic members apart from each other, the pair of magnetic members, which configure the closed magnetic path, form a square frame enclosing therein the insertion part, and the fixation member is bound to at least two adjoining side faces out of four side faces of the frame, and, also extends over a side face of the base part and the two side faces of the frame.
 3. The inductor according to claim 2, wherein the fixation member is a band-like member having a long side in the longitudinal direction and a short side in the widthwise direction, and is provided with a tacky adhesive layer having tackiness, and the fixation member is bound to the pair of magnetic members and the main body, while placing the tacky adhesive layer in between for adhesion.
 4. The inductor according to claim 3, wherein the fixation member extends over the longitudinal direction thereof around all of four side faces of the frame, to thereby bind the frame.
 5. The inductor according to claim 2, wherein the side faces of the base part bound with the fixation member are recessed inwardly from the side faces of the frame, or, aligned in the same plane with the side faces of the frame.
 6. The inductor according to claim 3, wherein the main body is configured by press-fitting a second member containing a cover part which covers the coil, onto a first member containing a plurality of terminal parts which are connected to the board, the side faces of the base part bound to the fixation member include a first plane contained in the first member, and a second plane contained in the second member, and the fixation member is bound across the first plane and the second plane.
 7. The inductor according to claim 6, wherein the fixation member is bound, across the widthwise direction thereof, to the side faces of the frame, the first plane and the second plane.
 8. The inductor according to claim 6, wherein the first member contains a hollow tubular article having the coil wound therearound, and having the insertion part inserted therein, the hollow tubular article is flanged at an end part thereof, the second member has a rib which is formed on the inner wall of the cover part so as to oppose to the end part, and so as to protrude from the inner wall towards the end part, and, the second member is press-fitted onto the first member along the end part so as to bring the end part into close contact with the rib.
 9. The inductor according to claim 8, wherein the end part contains an opening having the insertion part inserted therein, the rib extends nearly linearly along the inner wall of the cover part, and the rib extends at a position which falls outside the opening at the end part, when viewed whichever from the direction of press-fitting of the second member, or from the direction normal to the direction of press-fitting.
 10. The inductor according to claim 6, wherein an adhesive is coated on a boundary position between a part of the cover part which protrude from inside of the frame towards the opposite side of the base part, and the pair of magnetic members.
 11. The inductor according to claim 1, wherein the fixation member is made of a heat shrinkable material.
 12. The inductor according to claim 2, wherein the main body is configured by press-fitting a second member containing a cover part which covers the coil, onto a first member containing a plurality of terminal parts which are connected to the board, the side faces of the base part bound to the fixation member include a first plane contained in the first member, and a second plane contained in the second member, and the fixation member is bound across the first plane and the second plane.
 13. A method of manufacturing an inductor which has a pair of magnetic members, and a main body having a coil configured by a wound wire, the method comprising: configuring a closed magnetic path, by inserting a rod-like insertion part of one magnetic member, out of the pair of magnetic members, into the coil, and combining the one magnetic member with the other magnetic member to configure a closed magnetic path which includes as a part thereof the insertion part; and fixing the closed magnetic path, by binding a sheet-formed fixation member across the one magnetic member and the other magnetic member and the main body, to thereby fix the one magnetic member to the other magnetic member, both configuring the closed magnetic path, and to thereby fix at least one of the pair of magnetic members to the main body.
 14. The method of manufacturing an inductor according to claim 13, wherein the main body has a base part which is positioned, when mounted on a board, between the board and the pair of magnetic members so as to keep the board and the pair of magnetic members apart from each other, the fixation member is a band-like member having a long side in the longitudinal direction and a short side in the widthwise direction, and is provided with a tacky adhesive layer having tackiness, in the step of configuring the closed magnetic path, the pair of magnetic members are combined to form a square frame enclosing therein the insertion part, and in the step of fixing the closed magnetic path, the frame and the base part are aligned according to a desired positional relation, with reference to at least two adjoining side faces out of four side faces of the frame, the fixation member is adhered over the longitudinal direction thereof to the two faces, and, the fixation member is adhered across the widthwise direction thereof to the two faces and to the side face of the base part. 